c# - 如何全局访问当前的 HttpRequestMessage 对象？

Question

我有一个方法可以创建一个包含错误对象的 HttpResponseMessage，该对象将根据当前请求媒体类型格式化程序返回。

目前，我已经对 XmlMediaTypeFormatter 进行了硬编码，但我希望能够在运行时找到当前请求 MediaTypeFormatter 但我无权访问当前请求对象，因为我的以下代码存在于单独的类库中。

private HttpResponseMessage Create(HttpStatusCode statusCode, string errorCode, string errorMessage)
{
    var result = new HttpResponseMessage(statusCode)
        {
            Content = new ObjectContent<Error>(new Error()
            {
                Code = errorCode,
                Message = errorMessage
            }, new XmlMediaTypeFormatter())
        };
    return result;
}

如何全局访问当前的 HttpRequestMessage 对象？类似 HttpContext.Current.Request

如果不可能，如何实现上述方法，以便它知道应该为当前请求使用哪个格式化程序？

score 82 · Accepted Answer

正如我最近发现的那样，这并非不可能。它实际上是添加到当前 HttpContext 的 Items 属性中（如果有的话）=[

HttpRequestMessage httpRequestMessage = HttpContext.Current.Items["MS_HttpRequestMessage"] as HttpRequestMessage

编辑：

这是 WebAPI v2 的版本。我不能确定以前的版本。

score 1 · Accepted Answer

Why not do what the Web API team have done with their CreateResponse method? Make it an extension method of Controller. That way you can still have the code in a separate class library, but your method will have access to the controller instance and therefore all the Configuration information.

And on a slightly different note, I would suggest you look into some of the standardization efforts for error responses rather than inventing your own.

e.g.:

score 1 · Accepted Answer

您可以尝试使用 Autofac 对其进行归档，例如

public class MyPrincipal : IPrincipal
    {
        private readonly IPrincipal principal_;

        public MyPrincipal(ILifetimeScope scope)
        {
            if (scope.Tag == null || scope.Tag != MatchingScopeLifetimeTags.RequestLifetimeScopeTag)
            {
                throw new Exception("Invalid scope");
            }

            principal_ = scope.Resolve<HttpRequestMessage>().GetRequestContext().Principal;
        }
}

可以使用 InstancePerRequest 生命周期注册此类。

   builder.RegisterType<MyPrincipal>().As<IPrincipal>().InstancePerRequest();

c# - 如何全局访问当前的 HttpRequestMessage 对象？

3 回答 3

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